Trial Radial Head Implant

ABSTRACT

A trial orthopedic implant having a plurality of bearing component augments of differing heights, where each augment releasably, slidably connected to the trial implant.

BACKGROUND 1. Field of the Invention

The present invention relates generally to trial orthopedic implantdevices and systems and, more particularly to trial orthopedic implantdevices and systems for determining the height of a final radial headimplant.

2. Description of the Related Art

Some fractures of the radius occur in the part of the bone that isproximate the elbow, called the radial “head”. Radial head fractures arecommon injuries that may result from an acute elbow injury. Fractures ofthe radial head are typically treated with a variety of surgical andnon-surgical options depending upon the severity of the injury. Forexample, surgical options for more severe injuries to the radial headcan include open reduction with internal fixation (ORIF), radial headresection, hemi-arthroplasty (e.g., radial head arthroplasty), and totalarthroplasty (i.e., total elbow replacement).

Radial head arthroplasty involves resecting the fractured and damagedradial head and replacing the natural articulation with an artificialone by use of an implant. The implant articulates with the naturalcartilage surface of the capitellum of the distal humerus.

In radial head replacement procedures, a radial head prosthesis isimplanted into the intramedullary canal of the proximal radius. Theradial head may cooperate with an ulna or ulnar prosthesis to provideradioulnar joint articulation. The radial head may cooperate with ahumerus or humeral prosthesis to provide radiohumeral jointarticulation.

Prior to implantation of a radial head implant, a surgeon will need toselect an implant having a size that properly fits the implant site ofthe particular patient. Many known systems include trial stems and trialheads the surgeon can assemble and use prior to final implantation toevaluate the fit for selecting the most appropriately sized implant.However, known systems do not offer a simple effective means for tryinga plurality of different humeral head heights to determine the properheight for a final radial head implant. Exemplary systems include thefollowing prior art devices:

U.S. Pat. No. 6,746,487 discloses an intramedullary fixation device foruse in securing a trial in the medullary canal of a bone to determinethe offset and orientation of a prosthetic implant for replacement of ajoint articulating surface of the bone is disclosed. The fixation devicecomprises a body for receiving a trial and a fixation portion forengaging the trial. A system for use in surgical repair of a jointcomprising a selection of prosthetic implants of various sizes, aselection of trials of various sizes corresponding to the sizes of theimplants, a selection of fixation devices of various sizes correspondingto the sizes of the trials, a trial fixation device driver for insertingthe fixation device and attached trial into the canal of a bone, and atrial device extractor for removing the fixation device from theresected bone is disclosed. Methods of using the fixation device andsystem of the invention are disclosed.

U.S. Pat. No. 7,740,661 discloses radial head implant apparatuses andmethods. In one embodiment, a radial head implant can include a headportion for articular engagement with a humerus bone, a stem portion forengagement with a radius bone, and a shaft for engagement with the stemportion. The head portion can include an upper surface for engaging thehumerus bone. The stem portion can have an axial opening for receivingat least a portion of the shaft, and a collar can be disposed around thestem portion at a proximal end thereof. An upper portion of the shaftcan be configured for engaging the head portion, while a lower portionof the shaft can be elongated and cylindrical for axially fitting intoand moving within the axial opening of the stem portion. Otherembodiments are also disclosed for axial movement for a radial headimplant. Various structures are disclosed for locking the shaft inposition within the stem portion.

U.S. Pat. No. 8,535,382 discloses a prosthesis system for replacement ofa head portion of a proximal radius. The system can include a firstpolymeric articulation component having a first locking portion and ametal head component having a second locking portion. The second lockingportion can mate with the first locking portion to form a first lockingmechanism to initially couple the first articulation component to thehead component. The head component can define a locking channel. Thesystem can also include a stem component having a protrusion receivablein the locking channel. The protrusion can define a bore, and the stemcomponent can be adapted to be coupled to the radius. The system canalso include a fastener received through the locking channel and intothe bore to provide a second locking mechanism that couples the headcomponent to the stem component.

U.S. Pat. No. 8,764,845 discloses a kit for use in a procedure forimplantation of an orthopaedic joint prosthesis includes a headcomponent of an orthopaedic joint prosthesis, which comprises a bodypart having a convex bearing surface, and a reverse face at which thehead component can be connected to a mating component of the jointprosthesis, in which the head component has a chamfer surface extendingaround at least part of its periphery where the bearing and reversefaces come together, and a plurality of markings on the chamfer surface.The kit includes a trial head component which comprises a body parthaving a convex trial bearing surface and a reverse face, in which thetrial head component has a plurality of markings on the trial bearingsurface at or towards the interface between it and the reverse face. Thetransverse dimensions of the head component are approximately the sameas the transverse dimensions of the trial head component, and in whichthe location of the markings on the chamfer surface around the peripheryof the head component corresponds to the location of the markings on thetrial bearing surface of the trial head component around its periphery.

U.S. Pat. No. 8,840,676 discloses a prosthesis trial system includes atleast one head member having an outer surface and a cavity configured tomate with an exterior surface of a stem member. The prosthesis trialsystem further includes at least one shell member having an innersurface configured to mate with the outer surface of the at least onehead member.

U.S. Pat. No. 8,945,138 discloses a kit for use in performing a trialreduction in joint arthroplasty is provided. The kit includes a trialstem assembly including a first component, a second component selectablymoveable with respect to the first component, and a fastener forsecuring the first component to the second component. The kit alsoincludes an articulating trial component removeably fixedly secured tothe trail stem assembly and a driver for cooperation with the fastenerto secure the first component to the second component. The kit alsoincludes a handle. The handle has a first feature for permitting thedriver to pass through the handle and a second feature for orientablyconnecting the handle to the articulating trial component.

U.S. patent application publication no. 20040186580 discloses a radialhead replacement system includes a radial head replacement, an apparatusfor guiding the resection of a radial head, and a kit including boneplug and bone plug insertion instrument. The radial head replacement hasa separate adjustable head portion that may be secured on an implantedstem such that the implanted radial head replacement smoothly interfaceswith the capitellum of the humerus. In another form, the radial headreplacement uses crossed bone screws that serve to more securely anchorthe stem of the radial head replacement in the intramedullary canal ofthe radius. The resection guide includes a movable cutting guide whichensures a precise resection of the radial head and thereby allows forbetter positioning of the implanted radial head replacement. The boneplug limits the travel of bone cement beyond the area of affixation ofthe stem portion of a radial head replacement to the radius.

U.S. patent application publication no. 20050075735 discloses a modularprosthesis system for replacement of a head portion of a radius. Theprosthesis system includes a head component having a first connectionportion that connects to a second connection portion and a collarcomponent having the second connection portion and a third connectionportion. The system also includes a stem component including a fourthconnection portion that connects with the third connection portion, thestem component having a stem anchoring portion that connects to theradius. The collar component provides the modular geometry to theprosthesis without having to have an increased number of head componentsand stem components with variable lengths and angles.

U.S. patent application publication no. 20160051365 discloses a radialhead trial device for replacement of a proximal radial head includes astem component having a center longitudinal axis extending between aproximal end and a distal end, a head component axially and removablyattachable to the stem component, wherein the head component isinterchangeable with a selection of other head components each axiallyand removably attachable to the stem component, an anti-rotationfeature, and a recess, wherein the anti-rotation feature is structuredto be received in the recess to prohibit rotation of the head componentrelative to the stem component.

What is needed in the art is a trial radial head implant device andsystem that allows less joint distraction and a simpler device forconfirming final implant height.

SUMMARY

In one exemplary embodiment, the present invention is presented as atrial orthopedic implant assembly apparatus, said implant assemblyapparatus comprising: a radial implant component, said radial implantcomponent having a generally cylindrical head, said head having aheight, a concave articular proximal surface, an opposing flat distalsurface, a side wall, and a slot, said slot disposed through said wallof said head; said radial implant component further comprising a stem,said stem extending from said distal surface of said head; a headaugment, said augment having a generally cylindrical shape, a concavearticular proximal surface, an opposing distal concave mating surface,and a side wall, said augment having a height, where said height of saidaugment is less than the height of said head; said head augment furthercomprising a base, said base comprising an extension member, saidextension member having a first end connected to said mating surface ofsaid augment and extending vertically away from said mating surface ofsaid augment such that said extension member is perpendicular to saidmating surface of said augment, said extension member further comprisinga second end opposite said first end; and a tab, said tab extending fromsaid second end of said extension member, said tab perpendicular to saidextension member, said tab releasably slidably inserted and connectedinto said slot of said head component such that said mating surface isdisposed against said proximal articular surface of said head component.

In another exemplary embodiment, the present invention is presented as atrial orthopedic implant system, said implant system comprising: aradial implant component, said radial implant component having agenerally cylindrical head, said head having a height, a concavearticular proximal surface, an opposing flat distal surface, a sidewall, and a slot, said slot disposed through said wall of said head; astem, said stem extending from said distal surface of said head; aplurality of head augments, each head augment of said plurality ofaugments having a generally cylindrical shape, a concave articularproximal surface, an opposing distal concave mating surface, and a sidewall, and a unique height, where said height of each said augment ofsaid plurality of augments is less than the height of said head; eachsaid augment further having a base, said base comprising an extensionmember, said extension member having a first end connected to saidmating surface of said augment and extending vertically away from saidmating surface of said augment such that said extension member isperpendicular to said mating surface of said augment, said extensionmember further comprising a second end opposite said first end; and atab, said tab extending from said second end of said extension member,said tab perpendicular to said extension member, said tab releasablyslidably inserted and connected into said slot of said head componentsuch that said mating surface is disposed against said proximalarticular surface of said head.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will be understood more fully from the detaileddescription given hereinafter and from the accompanying drawings of thepreferred embodiment of the present invention, which, however, shouldnot be taken to limit the invention, but are for explanation andunderstanding only.

In the drawings:

FIG. 1 shows a side perspective exploded view of a trial radial implantapparatus and radial head augment apparatus in accordance with anexemplary embodiment of the present invention.

FIG. 2 shows another side perspective exploded view of a trial radialimplant apparatus and radial head augment apparatus in accordance withan exemplary embodiment of the present invention.

FIG. 3 shows a rear exploded view of a trial radial implant apparatusand radial head augment apparatus in accordance with an exemplaryembodiment of the present invention.

FIG. 4 shows a perspective view of a trial radial implant apparatus andradial head augment apparatus in accordance with an exemplary embodimentof the present invention.

FIG. 5 shows a side cross-sectional view of a trial radial implantapparatus and radial head augment apparatus in accordance with anexemplary embodiment of the present invention.

FIG. 6 shows a top cross-sectional view of a trial radial implantapparatus and radial head augment apparatus in accordance with anexemplary embodiment of the present invention.

FIG. 7 shows a side view of a trial radial head augment for a trialradial implant apparatus in accordance with an exemplary embodiment ofthe present invention.

FIG. 8 shows a trial radial head implant apparatus in accordance with anexemplary embodiment of the present invention.

Corresponding reference characters indicate corresponding partsthroughout the several views. The exemplary embodiments set forth hereinare not to be construed as limiting the scope of the invention in anymanner.

DETAILED DESCRIPTION OF THE EMBODIMENTS

The present invention will be discussed hereinafter in detail in termsof various exemplary embodiments according to the present invention withreference to the accompanying drawings. In the following detaileddescription, numerous specific details are set forth in order to providea thorough understanding of the present invention. It will be obvious,however, to those skilled in the art that the present invention may bepracticed without these specific details. In other instances, well-knownstructures are not shown in detail in order to avoid unnecessaryobscuring of the present invention.

Thus, all of the implementations described below are exemplaryimplementations provided to enable persons skilled in the art to make oruse the embodiments of the disclosure and are not intended to limit thescope of the disclosure, which is defined by the claims. As used herein,the word “exemplary” or “illustrative” means “serving as an example,instance, or illustration.” Any implementation described herein as“exemplary” or “illustrative” is not necessarily to be construed aspreferred or advantageous over other implementations. Moreover, in thepresent description, the terms “upper”, “lower”, “left”, “rear”,“right”, “front”, “vertical”, “horizontal”, and derivatives thereofshall relate to the invention as oriented in FIG. 1.

Furthermore, there is no intention to be bound by any expressed orimplied theory presented in the preceding technical field, background,brief summary or the following detailed description. It is also to beunderstood that the specific devices and processes illustrated in theattached drawings, and described in the following specification, aresimply exemplary embodiments of the inventive concepts defined in theappended claims. Hence, specific dimensions and other physicalcharacteristics relating to the embodiments disclosed herein are not tobe considered as limiting, unless the claims expressly state otherwise.

Referring now collectively to FIGS. 1-3, where there are shown aperspective exploded views of a trial radial implant apparatus 1000 andto FIG. 4, which shows a perspective assembly view of 1000, apparatus1000 generally comprises radial head augment 100 and radial head implant200. Augment 100 is adapted to be releasably attached to radial headimplant 200.

Referring now collectively to FIGS. 1-3, where there are shown aperspective exploded views of a trial radial implant apparatus 1000 andto FIG. 8, which shows a side view of implant 200, radial head implant200 comprises head 210. Head 210 has a cylindrical shape with a flatside walls 211, a generally flat distal surface 212, and a concave,proximal, articular surface 213 disposed opposite distal surface 212.Head 210 further comprises a height. Radial implant 200 furthercomprises stem 220. As shown in FIGS. 1-3 and 8, stem 220 is connected(preferably fixedly) to and extends from surface 212 of head 210.

Referring still to FIGS. 1-3 and 8, radial head implant 200 of assembly1000 further comprises slot 230 disposed through wall 211 of head 210.Slot 230 is adapted to releasably receive tab 115 of augment 100 asdescribed in greater detail below.

Referring now collectively to FIGS. 1-3, where there are shown aperspective exploded views of a trial radial implant apparatus 1000 andto FIG. 7, which shows a side view of augment 100, head augment 100 hasa generally cylindrical shape with a proximal (upper) concave articularsurface 113. Augment 100 further comprises a height. The height ofaugment 100 is less than the height of head 210. Augment 100 furthercomprises distal mating surface 112 disposed opposite proximal,articular surface 113. Mating surface 112 is preferably convex andadapted to nest against proximal articular surface 213 of head 210 ofradial implant 200.

Referring again to FIGS. 1-3 and 7, augment 100 further comprises a base114 having extension member 115. Extension member 115 is connected toand protrudes from distal, mating surface 112 of augment 100. Base 114further comprises a tab 116 extending from perpendicularly fromextension member 115. Tab 116 is generally parallel to mating surface112 of augment 100.

Referring next to FIG. 4-6, there are shown perspective, sidecross-sectional, and top assembly views respectively of assembly 1000 inaccordance with an exemplary embodiment of the present invention. Asillustrated in FIGS. 4-6, tab 116 is adapted to slidably, releasablyengage with slot 230 of head 210. As further illustrated in FIGS. 4-6,mating surface 112 of augment 100 is adapted to abut concave articularsurface 213 of head 210 when tab 116 of augment 100 is inserted intoslot 230 of head 210.

It is a further aspect of the present invention that a system inaccordance with the present invention may include a plurality ofaugments 100 wherein each augment 100 has a different unique height. Asurgeon can then use assembly 1000 to determine the desired height for anon-trial implant by trying augments 100 until a preferred size isidentified.

While this invention has been described with respect to at least oneembodiment, the present invention can be further modified within thespirit and scope of this disclosure. This application is thereforeintended to cover any variations, uses, or adaptations of the inventionusing its general principles. Further, this application is intended tocover such departures from the present disclosure as come within knownor customary practice in the art to which this invention pertains andwhich fall within the limits of the appended claims.

1. A trial orthopedic implant assembly apparatus, said implant assemblyapparatus comprising: a radial implant component, said radial implantcomponent having a generally cylindrical head, said head having aheight, a concave articular proximal surface, an opposing flat distalsurface, a side wall, and a slot, said slot disposed through said wallof said head; said radial implant component further comprising a stem,said stem extending from said distal surface of said head; a headaugment, said augment having a generally cylindrical shape, a concavearticular proximal surface, an opposing distal concave mating surface,and a side wall, said augment having a height, where said height of saidaugment is less than the height of said head; said head augment furthercomprising a base, said base comprising an extension member, saidextension member having a first end connected to said mating surface ofsaid augment and extending vertically away from said mating surface ofsaid augment such that said extension member is perpendicular to saidmating surface of said augment, said extension member further comprisinga second end opposite said first end; and a tab, said tab extending fromsaid second end of said extension member, said tab perpendicular to saidextension member, said tab releasably slidably inserted and connectedinto said slot of said head component such that said mating surface isdisposed against said proximal articular surface of said head component.2. A trial orthopedic implant system, said implant system comprising: aradial implant component, said radial implant component having agenerally cylindrical head, said head having a height, a concavearticular proximal surface; an opposing flat distal surface, a sidewall, and a slot, said slot disposed through said wall of said head; astem, said stem extending from said distal surface of said head; aplurality of head augments, each head augment of said plurality ofaugments having a generally cylindrical shape, a concave articularproximal surface, an opposing distal concave mating surface, and a sidewall, and a unique height, where said height of each said augment ofsaid plurality of augments is less than the height of said head; eachsaid augment further having a base, said base comprising an extensionmember, said extension member having a first end connected to saidmating surface of said augment and extending vertically away from saidmating surface of said augment such that said extension member isperpendicular to said mating surface of said augment, said extensionmember further comprising a second end opposite said first end; and atab, said tab extending from said second end of said extension member,said tab perpendicular to said extension member, said tab releasablyslidably inserted and connected into said slot of said head componentsuch that said mating surface is disposed against said proximalarticular surface of said head.